1. Field of Invention
The present invention relates to a method of manufacturing a metal oxide semiconductor, and more particularly to a method of forming a compressive nitride film and a method of manufacturing a metal oxide semiconductor (MOS).
2. Description of Related Art
With semiconductor processes entering the era of the deep submicron meter, since increasing the NMOS and PMOS drive current will greatly improve the time-delay performance of transistor elements, a process for manufacturing a semiconductor of a size below 65 nm has been more and more important for increasing the NMOS and PMOS drive current. For example, there is conventional research on developing an ILD low dielectric constant (low k) material to increase the drive current. Recently, research on the influence of a shallow trench isolation (STI) oxide layer, the silicon nitride (SiN) stressor of the poly-cap, and the film stress of a SiN contact etching stop layer (SiN CESL) upon the drive current of transistor elements has appeared domestically and abroad.
As a result, the STI oxide, SiN stressor of the poly-cap, and the film stress of the SiN CESL are deposited into a compressive stress. The more the film is compressed, the more the PMOS drive current increases.
However, so far, through PECVD and at a temperature lower than 400° C., the most well-known As-deposit technology in the world can only reach −1.6 GPa. Therefore, how to further obtain a film with higher compressive stress has become a research issue in various fields.